Also notice that
> "+5" < 0
[1] TRUE
> as.numeric("+5") < 0
[1] FALSE
So the presumption is wrong. It is really about
> sort(c(0:3, "+", "-"))
[1] "-" "+" "0" "1" "2" "3"
-pd
> On 25 Jun 2024, at 10:02 , Martin Maechler <maech...@stat.math.ethz.ch> wrote:
>
>>>>>> Adrian Dusa
>>>>>> on Tue, 25 Jun 2024 10:56:07 +0300 writes:
>
>> Dear R fellows,
>
>>> From time to time, just when I thought I knew my R, I get
>>> bitten by some
>> small things that reminds one to constantly return to the
>> basics.
>
>> I knew for instance that "-1" < 0 is TRUE, presumably
>> because R first coerces to numeric before comparing with
>> 0.
>
>> But I did not expect that "--" < 0 is a TRUE statement.
>> (and the same holds for any string prepended by a minus
>> sign, e.g. "-a" < 0)
>
>> I would be grateful for an explanation, I'm sure that
>> something very obvious escapes me but it sure does seem
>> counter intuitive to me.
>
>> Best wishes, Adrian
>
>> [[alternative HTML version deleted]]
>
> Nice, quiz, yes.
>
> You must have forgotten that all Op's (+,-, <= , &, | ..)
> must coerce to common type.
>
> ... and so does c() where coercion is defined a bit more.
>
> --> does c("--", 0) give you a clue, now ?
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd....@cbs.dk Priv: pda...@gmail.com
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